Wire straightening apparatus



Dec. 17, 1963 J. o. HINKLE IETAL 3,

WIRE STRAIGHTENING APPARATUS Filed June 30, 1961 2 Sheets-Sheet 1 W InDec. 17, 1963 J. o. HINKLE. ETAL 3,114,400

v WIRE smrcnmumc APPARATUS Filed June 30, 1961 r 2 Sheets-Sheet 2 UnitedStates Patent York Filed June 30, 1961, Ser. No. 121,035 3 Claims. (Cl.140147) This invention relates to the straightening of elongatedobjects, and more particularly to a novel apparatus for insuring thtestraightness of fine wires eventually bent to an S configuration andused in point contact diodes.

Difficulty has been encountered with deviation of the fine tungstenwires used in point contact diodes, after the S bend has been formedtherein, from the eye plane (a plane including the axis of the pinassembly upon which the wire is mounted, as by soldering), and thereasonfor such deviation has been determined to reside in deviation of thewire from a position coincident with the axis of the pin assembly priorto the formation of the S bend therein. Further, such deviation of the Sbent wire from this eye plane has been discovered to promote skidding ofthe wire across the surface of the semi-conductor body against which oneend of the wire bears in the completed diode assembly, resulting inundesirable scratching of such surface and attendant high reversecurrents during test operation of the diode necessitating rejectionthereof as unsatisfactory.

It is, accordingly, an object of this invention to effect thestraightening of elongated objects, such as fine tungsten wires, in themanner more fully set forth hereinbelow.

Another object of the invention is to enable the straightening of suchobjects to be achieved rapidly and automatically and as an integratedstep in the operation of a diode wire soldering and S bend machine.

A further object of the invention is to eliminate the above-mentionedundesirable high reverse currents in the performance of the completeddiode by insuring the straightness of the fine tungsten wires prior tothe formation of the S bend therein.

The invention generally comprises a straightening means which isautomatically positioned into engagement with the wire, to deflect thewire to a slight degree, simultaneously with the automatic positioningof a rotating drive means into engagement with the rotatable holdingmeans in which the pin assembly is supported, thus efiecting therotation of the wire while in a slightly deflected position against thesurface of such straightening means. Upon the automatic withdrawal ofthe straightening means and rotating drive means, the wire springs backto a straight position coincident with the axis of the pin assembly uponwhich same is mounted.

The invention and the advantages thereof may be more readily understoodby reference to the accompanying drawings, wherein:

FIG. 1 is a side plan view, partially in section, showing thestraightening apparatus of the present invention; and

FIG. 2 is an end view, partially broken away, showing the driving wheel.

Referring now to FIGS. 1 and 2, the spin station subassembly, generallyindicated at 50, is seen to be positioned adjacent to the periphery andupper and lower faces of a rotatable work support table 1, which tableis indexed to the various stations during operation of the wiresoldering and S bend machine. Spindle housing 2 is mounted on the upperface of the work support table and secured thereto through mountingelement 51 by bolt 52. A pin assembly holding spindle 53 is rotatablymounted in the spindle housing and includes a knurled, annular drivesurface 54 formed at the lower end thereof.

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Diode pin assembly 3, which includes the tungsten wire 4, is fixedlysupported within this rotatable spindle.

Mounted beneath the work support table on main frame member 5, almostdirectly below the spindle housing 2, a double acting air cylinder 6having air inlets 7 and 8 and a piston rod extension 9.

Motor support plate 12 is connected to the end of the piston rodextension and movable therewith, and to this efiect is slidably mountedwithin support members 11 and 15 in the manner shown at 13 in FIG. 2.Electric motor 16 is mounted on the support plate 12 and secured theretoby bolts 18. Straightening finger support members 19, 21, and 22 andguard 23 are mounted on the motor in the manner depicted. Straighteningfinger 24 is mounted atop straightening support member 22 and attachedthereto by bolts 26.

Electric motor 16 is seen to further comprise power transmission meanshousing 27 from which projects power shaft 30. Driving wheel 28 ismounted upon such shaft as shown and secured thereto by pin 29. Rubber 0ring 31 is positioned around the periphery of the driving wheel andsecured thereto in any convenient manner, as for example, by a stretchfit or adhesive bond.

Operation Upon the completion of the wire soldering step at a previousstation, the work support table 1 is automatically indexed to theposition depicted in FIGS. 1 and 2. Once the table has assumed suchposition, control means, not shown, eifect the supply of compressed airto air cylinder inlet 8, thus shifting the motor 16 and'straighteningfinger 24 to the position depicted in FIG. 1 wherein the rubber O ring31 is seen to be in frictional driving engagement with the knurledspindle drive surface 54 and the straightening finger in engagement withtungsten wire 4.

The driving engagement between the rotating 0 ring and the rotatablespindle results in rotation of the latter with attendant rotation of thetungsten wire, in a deflected position, against the surface of thestraightening finger. Upon the expiration of a predetermined period oftime (approximately 1.5 seconds), control means, not shown, effect thesupply of compressed air to air cylinder inlet 7 to shift the motor 16and straightening finger 24 to the right in FIG. 1 to remove the rubberO ring from engagement with the spindle drive surface and thestraightening finger from engagement with the wire.

It is to be noted that if the wire is straight prior to the operation ofthe instant device, he deflection occasioned by contact with thestraightening finger will be within the elastic range, that is to saythe wire will be deflected slightly but spring back to its originalstraight position once the straightening finger has been withdrawn. If,however, the wire is not straight originally, as is the more probablecircumstance, the deflection occasioned by the contact with thestraightening finger will extend the wire past the elastic limit intothe plastic range so that some measure of permanent deformation (thatnecessary to substantial straightness of the wire) will occur thusinsuring that the wire springs back to a straight position, whichstraight position is, of course, different from that which it occupiedprior to the deflection by the straightening finger.

Various changes and modifications may obviously be made in the disclosedembodiment without departing from the spirit and scope of the invention.

What is claimed is:

1. In an apparatus for straightening an elongated object, a work supporttable, a holding chuck rotatably mounted upon said work support tablefor holding the object, a motor assembly including friction drive meansand a straightening finger mounted adjacent said rotata- Patented Dec.17, 1963.

e") ble holding chuck, said straightening finger comprising a deflectingsurface of significantly lesser extent than the object as measured alongthe axis of the latter and said motor assembly being slidable in adirection substantially perpendicular to said axis to at least twopositions in one of which the friction drive means are in drivingengagement with the holding chuck to effect rotation of the object aboutits longitudinal axis and the deflecting surface is in engagement withthe elongated object to effect deflection thereof and in the other ofwhich no such engagements occur, and positioning means connected to themotor assembly and operative to selectively position the said assemblyin either of the two said positions.

2. A device for straightening elongated objects comprising a rotatableholder including a chuck for holding an elongated object to bestraightened and having a driven member connected thereto, an assemblymounted adjacent the holder and including a straightening finger fordeflecting the elongated object and a driving member for drivinglyengaging the driven member, and means for causing relative movementbetween the assembly and the holder in one direction to cause the fingerto engage the elongated object and effect the deflection thereof whilesimultaneously causing the engagement of the driven and driving membersto effect the rotation of the elongated object and in the oppositedirection to move the finger away from the elongated object causingdisengagement of the driving and driven members.

3. A device for straightening elongated objects comprising a rotatableholder including a chuck at one end thereof for holding a wire to bestraightened and a circular driven member connected to the chuck at theopposite end thereof, a slidable assembly mounted adjacent the holderand including a straightening finger for deflecting the wire and acircular friction driving member for drivingly engaging the drivenmember, and means for sliding the assembly in one direction to cause thefinger to engage the wire and effect the deflection thereof andsimultaneously cause the engagement of the driven and driving members toeffect the rotation of the wire and for sliding the assembly in theopposite direction to move the finger away from the wire and to causedisengagement of the driving and driven members.

References Cited in the file of this patent UNITED STATES PATENTS331,386 Eames Dec. 1, 1885 934,429 Davies Sept. 21, 1909 2,120,877 UberJune 14, 1938 2,389,885 Anderson Nov. 27, 1945 2,505,924 Varga May 2,1950 2,964,087 Riese Dec. 13, 1960

2. A DEVICE FOR STRAIGHTENING ELONGATED OBJECTS COMPRISING A ROTATABLEHOLDER INCLUDING A CHUCK FOR HOLDING AN ELONGATED OBJECT TO BESTRAIGHTENED AND HAVING A DRIVEN MEMBER CONNECTED THERETO, AN ASSEMBLYMOUNTED ADJACENT THE HOLDER AND INCLUDING A STRAIGHTENING FINGER FORDEFLECTING THE ELONGATED OBJECT AND A DRIVING MEMBER FOR DRIVINGLYENGAGING THE DRIVEN MEMBER, AND MEANS FOR CAUSING RELATIVE MOVEMENTBETWEEN THE ASSEMBLY AND THE HOLDER IN ONE DIRECTION TO CAUSE THE FINGERTO ENGAGE THE ELONGATED OBJECT AND EFFECT THE DEFLECTION THEREOF WHILESIMULTANEOUSLY CAUSING THE ENGAGEMENT OF THE DRIVEN AND DRIVING MEMBERSTO EFFECT THE ROTATION OF THE ELONGATED OBJECT AND IN THE OPPOSITEDIRECTION TO MOVE THE FINGER AWAY FROM THE ELONGATED OBJECT CAUSINGDISENGAGEMENT OF THE DRIVING AND DRIVEN MEMBERS.